Performance Of Hot Mix Asphalt Research Articles

Evaluation of effects of soybean derived oil and aggregate petrology on the performance of asphalt mixes

The realistic prediction of long term performance of hot mix asphalt (HMA) has been a challenging task for the pavement industry. This study aims to investigate the effect of soybean derived oil and aggregate petrology on the HMA performance. The properties of HMA were evaluated using Superpave gyratory compactor (SGC), indirect tensile (IDT) strength, dynamic modulus and semicircular bend (SCB) tests. The SGC results indicated that soybean derived oil has no adverse effect on compaction of HMA. The tensile strength ratio (TSR) analysis showed that the presence of quartz and feldspar in aggregates could affect the durability of HMA. The TSR results found that soybean oil improved resistance of HMA against moisture susceptibility. The SCB test results showed that the soybean oil improved the fracture resistance of asphalt mixes. The dynamic modulus results revealed that soybean derived oil decreased the stiffness of HMA.

Influence of Recycled Concrete Aggregate (RCA) towards the Performance of Hot-Mix Asphalt (HMA) Mixture

Influence of Recycled Concrete Aggregate (RCA) towards the Performance of Hot-Mix Asphalt (HMA) Mixture

Correlating the asphalt-binder high-temperature properties (DSR) to HMA permanent deformation (RLPD) and field rutting: A laboratory-field study

Asphalt-binders are part of the key material constituents affecting the performance of hot-mix asphalt (HMA), and ultimately, the field performance of flexible pavement structures. Quite often, it is desired/useful to predict the HMA permanent deformation (viscoelastic) properties and field rutting from the asphalt-binder properties. Using the Texas flexible pavements and overlays database, namely the Texas Data Storage System (DSS), as the data source, this laboratory-field study was conducted to correlate the asphalt-binder properties to HMA permanent deformation (viscoelastic) properties and field HMA-layer rutting performance of in-service highway sections. Data extracted from the Texas DSS included asphalt-binder high-temperature rheological properties measured using the dynamic shear Rheometer (DSR) test, HMA permanent deformation (PD) and viscoelastic properties from the repeated load permanent deformation (RLPD) test, and field rut depth (RD) data for the HMA layers of in-service highway test sections. Two Texas asphalt-binder types, four HMA mixes, and four in-service field highway sections were used in the study. For some parametric comparisons, the corresponding results indicated good statistical correlations among the asphalt-binders, HMA mixes, and field rutting performance, with a coefficient of determination (R2) over 60%. Overall, the study findings indicated that the HMA PD properties and field HMA-layer rutting can be predicted from the asphalt-binder high-temperature rheological properties, with a linear or logarithmic model, to an accuracy exceeding 60%.

An evaluation of the performance of hot mix asphalt containing calcium carbide residue as a filler

The reduction of both environmental problems and construction costs has motivated the asphalt pavement industry to increasingly use waste materials as alternative raw materials in road pavements construction. This investigation aims to explore the potential of waste calcium carbide residue (CCR) for use as a filler in hot mix asphalt (HMA), by substituting traditional limestone filler in various proportions. Asphalt mixes were prepared using different CCR ratios (0%, 3% and 6%) by aggregate dry weight, their strength, properties and performance evaluated against the indirect tensile stiffness modulus, rutting, crack initiation, crack propagation and moisture damage. The results show that stiffness modulus and resistance to permanent deformation and cracks have been enhanced due to the addition of CCR. HMA modified with CCR was also found to be less sensitive to water damage than traditional HMA with limestone filler. A toxicity characteristic leaching procedure (TCLP) test revealed that the CCR used in the production of HMA has no environmental impact. Therefore, based on this study, CCR can be considered as a plausible alternative to conventional filler in HMA, the implication being that large amounts of waste carbide lime can be removed from landfill, thereby significantly reducing environmental damage.

Effects of different fillers on pavement deformation of hot mix asphalt in hot climates

Permanent deformation in the form of rutting is one of the major distresses affecting flexible asphalt pavements. This is a serious issue in hot countries and is closely associated with the viscosity of the bitumen binders used. In hot countries, temperatures can exceed 45 °C. Even in the construction of primary roads, bitumen 60/70 (B60/70), which is a relatively low-grade and soft bitumen, continues to be used for Hot Mix Asphalt (HMA) construction. Libyan asphalt concrete pavement roads therefore develop extreme deformations in the form of rutting. This study tests the effects of filler materials on mechanical and volumetric HMA performance with recourse to cellulose fiber (CF) and Ordinary Portland Cement (OPC). CF and OPC were added to a B60/70 HMA mix according to Superpave design specifications. Three percentages of OPC (2%, 4%, and 6%) and three different percentages of CF (0.25%, 0.5%, and 0.75%) were used as filler; there was also a control mix with no filler (0%). Mix performance was assessed with the rutting analyzer and The Indirect Tensile Stiffness Modulus (ITSM). ITSM test were conducted at −5 °C, 10 °C, 25 °C and the rutting analyzer test was conducted at 60 °C to simulate temperatures in the region. The mixes using cellulose fiber performed better than those with OPC. The results suggest potential budgetary savings because roadworks projects can use inexpensive additives instead of more expensive bitumen binders.

Evaluation of recycled asphalt mixtures rejuvenated with Madhuca longifolia (Mahua) oil

Reuse of reclaimed asphalt pavement (RAP) material not only leads to environmental sustainability, but also lowers down the of construction cost. However successful addition of RAP is limited to replacement level of 50%, as it is believed that higher quantity of the RAP makes the asphalt more susceptible to fatigue and thermal cracking. Studies on rejuvenation of aged binders recommend that it is possible to use higher percentage of RAP by using recycling agents or rejuvenators. Different types of oils such as vegetable oil, tall oil, cotton seed oil, waste engine oil, pongamia oil and soybean oil etc. have been explored as rejuvenators. In this study, Madhuca longifolia oil (Mahua oil), another oil produced largely in eastern part of India has been assessed as a potential rejuvenator to design recycled Hot Mix Asphalt (HMA) with high RAP content. Suitable dosage of the rejuvenator was decided based on the evaluation of rheological characteristics of the rejuvenated aged binder using a Dynamic Shear Rheometer (DSR). Performance of the conventional asphalt mixture and rejuvenated mixtures containing RAP with varying (30–70%) RAP percentages was assessed in terms of volumetric properties, indirect tensile strength, moisture sensitivity, resilient modulus, rutting, fatigue, low temperature cracking. Results were compared with the performance of recycled HMA made using softer binder grade. Results indicate that recycled mixtures with RAP content up to 60% can be successfully designed with addition of Madhuca longifolia oil to meet the without notably influencing the performance of the pavement.

Evaluating fatigue performance of hot-mix asphalt using degradation parameters

Hot-mix asphalt (HMA) suffers a reduction in stiffness and strength under repeated cyclic loading, such that it eventually cracks. This paper reports the measurement of asphalt fatigue degradation in terms of stiffness modulus and dissipated strain energy (DSE). Three degradation rate parameters were derived from the linear parts of the relationships against a number of cycles: normalised stiffness modulus from the traditional approach (TA), and DSE and cumulative dissipated strain energy (CDSE) from the energy concept approach. Three techniques were used to perform the fatigue test: dynamic shear rheometer, two- and four-point bending tests. Different asphalts were made from open and dense gradings of limestone and granite aggregates, and with soft and hard binders according to British standards. The tests revealed that the DSE and CDSE degradation parameters were incompatible with the TA in the strain-controlled test mode, but compatible in the stress-controlled test mode. The variation and scattering of all degradation parameters was relatively low. In conclusion, the normalised stiffness modulus degradation rate parameter looks most promising for evaluating and predicting the fatigue performance of HMA regardless of the test technique and mode.

Laboratory Performance Evaluation of Hot-Mix Asphalt Mixtures with Different Design Parameters

Aggregate gradation and asphalt type are traditional variables that affects mix design of Hot-Mix Asphalt (HMA). Recently, the number of design gyrations (Ndes) has been increasingly accepted as another variable parameter during the design process. Due to the growing shortage of high-quality raw materials, it is necessary to make full use of the combined roles between these design parameters, instead of solely relying on their individual effect, to improve the HMA properties. Therefore, this study comprehensively explored the effect of aggregate gradation, Ndes, and asphalt type on the performance of HMAs. Seven different combinations of aggregate gradation, Ndes, and asphalt type were evaluated. The volumetric indicators, uniaxial penetration shear test (UPST), unconfined compression test (UCT), low-temperature bending test (LBT), four-point bending test (FPBT), and dynamic modulus test (DMT) were used to assess the performance of HMAs designed by various parameter combinations. It was found that the contribution of adopting harder asphalt binder was able to make up for the high-temperature resistance loss caused by lower Ndes or coarser gradation. The dynamic modulus exhibited the similar phenomenon. By contrast, the harder asphalt binder led to the worse tenacity of HMAs at low temperature; however, the tenacity can be restored through using lower Ndes or coarser gradation by increasing asphalt content. In addition, the fatigue life of HMAs went up significantly by about 36 ~ 41%, when both Ndes and asphalt penetration grade decreased to one lower level.

Preliminary Evaluation of Hot Mix Asphalt Containing Reclaimed Epoxy Asphalt Materials

Designing long-life pavements and pavement recycling with reclaimed asphalt pavement (RAP) are two important strategies for improving the sustainability of asphalt pavements. Epoxy asphalt, as a proven long-life pavement material, is attracting attention from the pavement community for its use in road pavements. The recyclability of epoxy asphalt mixtures, however, has never been studied and has now become one concern in promoting the use of epoxy asphalt in road pavements. This study attempts to explore the performance of hot mix asphalt (HMA) containing reclaimed epoxy asphalt materials. Reclaimed epoxy asphalt was fabricated in the laboratory and incorporated into regular asphalt mixtures at various contents. Specimens were prepared and tested for their performance in comparison with mixtures without RAP. It was found that replacing the coarse aggregates in HMA with epoxy RAP up to 80% did not negatively affect its Marshall stability, tensile strength, and moisture resistance. The plastic deformation at failure of HMA, however, may increase with the increase in epoxy RAP content. At the current stage, the results from this study do not provide evidence to invalidate the use of epoxy RAP in HMA, at least at a coarse aggregate replacement rate of less than 40%.

Investigating The Effect of Acrylic Latex on Moisture Susceptibility of Hot Mix Asphalt

Polymers are popular materials as an additive to improve the performance of hot mix asphalt (HMA). To this aim, acrylic latex was chosen to improve the performance of asphalt mixture. In this study, it was investigated that the performance of hot mix asphalt with acrylic latex additive in three percentages (1%, 2% and 3%). Design bitumen contents were determined for all acrylic latex additive. Indirect Tensile Strength and moisture susceptibility of acrylic latex added HMA was conducted using test procedure of AASHTO T283. According to the results, design bitumen contents were increased by acrylic latex. Although the bitumen content was increased, both the indirect tensile (IDT) strength and the moisture resistance were improved by acrylic latex. Best performance was obtained by 3% acrylic latex additive. It is suggested that the percentage of acrylic latex would be increased for further researches.

Temperature Effect on the Deformation of the Recycled Hot-Mix Asphalt Concrete with Nano Crumb Rubber as an Added Material with Wheel Tracking Machine

The use of materials for the construction of roads can be done by recycling asphalt concrete mixtures that have reached fatigue or aging conditions. The results from stripping the asphalt concrete layer on the surface layer can be reused after processing by recycling the material. The recycling process is often intended to preserve the environment from natural damage due to the processing of material for asphalt concrete mix. To improve the performance of the recycled mixture, additives have been widely used and the use of building materials as additives can also be obtained from building material waste. One of the waste that continues to increase is the waste of vehicle tires. In this research used tire waste that has been mashed up to Nano size. The use of finer used tire sizes is intended to facilitate the process of mixing with asphalt. Recycling performance of hot mix asphalt concrete on deformation performance has been used rutting test using Wheel Tracking Machine at a temperature of 27°C, 40°C and 60°C. The test results showed a decrease in the rate of deformation in the asphalt concrete recycle mixture using Nano crumb rubber added material.

Assessment of the Impact of Fiber Types on the Performance of Fiber-Reinforced Hot Mix Asphalt

This study aims to evaluate the impact of fiber types on the performance of hot mix asphalt (HMA) mixtures. Specifically, the impacts of fiber type on HMA mix design and laboratory performance are investigated. Four types of fiber (fiberglass, basalt, carbon, and polyolefin/aramid blend) were used to produce four fiber-reinforced HMA mixes, and a control mix without fibers was also prepared. The fiber dosage rates used in this study were 0.16% (fiberglass, basalt, and carbon) and 0.05% (polyolefin/aramid) by total mixture weight, based on manufacturer recommendations. Two mixing procedures for introducing fibers into HMA were also evaluated: dry and 15-s dispersion methods. The dry method involved mixing the fibers with aggregates before the addition of asphalt binder while the 15-s dispersion method involved adding the fibers into the mix every 15 seconds (as aggregates were coated by asphalt binder during the mixing process). All the HMA mixtures (unreinforced and fiber-reinforced) were then subjected to several different laboratory performance tests: dynamic complex modulus, Cantabro durability, asphalt pavement analyzer, flow number, and indirect tensile strength. Analysis of variance was conducted to evaluate statistically the impact of fibers on mix performance. Results showed that fibers affected the volumetric properties, mix durability, and rutting resistance of HMA mixes. It was also found that the process for introducing fibers into the mix (i.e., mixing method) affected the consistency of fiber-reinforced HMA samples. Overall, the results of this study showed that the use of fibers improved the rutting and durability performance of asphalt mixtures in the laboratory.

Employment of Mechanical Testing to Evaluate the Effect of Density on Asphalt Pavement Performance

Abstract Considering the budget allotted to construct and maintain roadway surfaces, a 5 to 10 % increase in their performance could potentially yield annual savings of billions of dollars. Considering this, the Kentucky Transportation Cabinet (KYTC) launched a project to better understand the effect of in-place density on the durability of their hot-mix asphalt (HMA) pavements. In-place density is known to be a crucial factor in HMA performance. The Asphalt Institute in cooperation with the KYTC embarked upon the research and collected numerous HMA samples from five pavement construction sites in Kentucky. An experimental laboratory plan was developed to examine potential improvement in the mixtures’ performance if they were compacted to a desired higher density. The laboratory test plan consisted of flow number, flexural beam fatigue, and disk-shaped compact tension tests to evaluate the mixtures’ performance with respect to rutting, fatigue cracking, and low-temperature cracking. A statistical analysis of the results was performed to evaluate the effect of density on the durability of each of the pavements. The results showed that the service life of the pavements could improve considerably by achieving a target density of 92 %. The compactibility of the HMA mixtures was also investigated through their compaction characteristic curves by using the Superpave gyratory compactor. Based upon the compactibility analysis, the mixtures could be better compacted in the field by increasing their lift thickness.

Study the effect of adding crumb rubber on the performance of hot mix asphalt

The recycling of materials has a huge impact on the economy and the environment; therefore, the recycling of steel, aluminium, plastic and other materials have been encouraged to use in construction materials. Crumb rubber is one of these recyclable materials and has been proposed as one of the pavement components in this study since the crumb rubber can improve the pavement performance and is also considered as waste material. The most significant motivation behind use of the CRM in the pavement industry was the enhancement of pavement performance and extended service life of the pavement by increasing the resistance to moisture damage and resistance to permanent deformation and improved resilient modulus. Therefore, this study focused on the effect of CRM binders on the performance and mechanical properties of the hot mix asphalt. The CRM binders were produced by mixing asphalt binder with various percentages of crumb rubber in a wet method. There are several laboratory tests performed to assess the properties and performance of asphalt mixture, which contains various percentages of crumb rubber, and this, includes; the Marshall properties, indirect tensile strength test, moisture damage test, resilient modulus test and permanent deformation test. In this study, the results of the investigation showed that the addition of crumb rubber (CR) to the asphalt binder and used in the mixture was useful in increasing the resistance to moisture damage, improving the resilient modulus and enhancing the potential to resist permanent deformation that happens in the surface layer of the pavement as a result of increased traffic loading.

Influence of Antistripping Additives and Rejuvenators on Healing Performance of Moisture‐Damaged HMA

This study aims to evaluate the effect of different rejuvenators and antistripping agents on the healing performance of hot mix asphalt (HMA). Two damage HMA series (e.g., moisture damage and aged damage) were subjected to either induction or microwave heating. A PG64‐22 virgin and aged binder were used and modified with several additives. Three long‐term aged binders (e.g., PAV5, PAV15, and PAV20) were conducted by pressure aging vessel (PAV) test. The moisture damage series fabricating with a new binder was further categorized into four different freeze‐thaw (FT) cycles (e.g., 0FT, 1FT, 3FT, and 5FT). Also, the aged series was fabricated with three different aged binders. A total of eight damage‐healing cycles were applied to all asphalt mixtures, examined by the three‐point bending test. The moisture resistance of modified asphalt mixture was examined by indirect tensile strength test. Overall, asphalt mixtures modified with either antistripping additives or rejuvenators not only obtained higher moisture resistance but also gained better healing performance under moisture damage. In addition, the study showed a probable correlation between moisture damage and long‐term aging in terms of healing performance, such as PAV15 and 3FT cycles and PAV20 and 5FT cycles.

The effect of polyolefin-aramid fibers on performance of hot mix asphalt

In this study, polyolefin-aramid fibers were used as an additive to modify the performance properties of asphalt mixtures. For this purpose, three percentages of the fiber (i.e., 0.025%, 0.05%, and 0.075%) were added to asphalt mixtures and the rutting, fatigue and cracking performance of the mixtures were evaluated using the dynamic creep, wheel track, indirect tensile fatigue, and semi-circular bending (SCB) fracture tests. The results showed that the rutting and cracking resistance improved incrementally by increasing the fiber content, and the fatigue performance enhanced by adding up to 0.05% fiber and then leveled out by increasing the amount of fiber.

Rutting and Moisture Damage Evaluation of Warm Mix Asphalt Incorporating POFA Modified Bitumen

The unwanted disposal Palm Oil Fuel Ash (POFA) can be minimised through its application in road construction. Available literatures have shown that POFA improves the performance of hot mix asphalt (HMA), however, its application in warm mix asphalt (WMA) remains unexplored. This study was carried out to investigate the performance of WMA with POFA modified bitumen. In this study, Five percent POFA and 0.75% Evotherm is blended with 60/70 PEN grade bitumen to produce warm POFA modified bitumen (B3). The B3 binder is subjected Fourier Transform Infrared spectroscopy (FTIR), Atomic Force Microscopy (AFM), and Contact angle measurements to understand the effect of this modification at microstructural level. Also, the binder is used in preparing dense graded asphalt concrete (AC14) at 140/130 ℃ mixing/compaction temperatures rspectively. Mixture performance tests such as Marshall flow and stability, dynamic creep, Asphalt Pavement Analyser (APA), tensile strength ratio, and boiling water tests were used to examine the resistance of B3 binder to rutting and moisture damage. Results from dynamic creep and APA test shows that the WMA mixtures possess 30% improved rutting resistance than the conventional HMA. On the contrary, the WMA sample parade lower resistance to moisture damage by 10% as revealed by the tensile strength ratio test. All the tested samples satisfied the specification limits for AC14 mixture, thus alleviating any concern regarding the moisture damage vulnerability of WMA mixtures.

Characterization of Asphalt Mixtures Produced with Coarse and Fine Recycled Asphalt Particles

Utilizing recycled asphalt pavements (RAP) in pavement construction is known as a sustainable approach with significant economic and environmental benefits. While studying the effect of high RAP contents on the performance of hot mix asphalt (HMA) mixes has been the focus of several research projects, limited work has been done on studying the effect of RAP fraction and particle size on the overall performance of high RAP mixes produced solely with either coarse or fine RAP particles. To this end, three mixes including a conventional control mix with no RAP, a fine RAP mix (FRM) made with 35% percent fine RAP, and a coarse RAP mix (CRM) prepared with 54% of coarse RAP were designed and investigated in this study. These mixes were evaluated with respect to their rutting resistance, fatigue cracking resistance, and low temperature cracking performance. The results indicate that although the CRM had a higher RAP content, it exhibited better or at least the same performance than the FRM. The thermal stress restrained specimen testing (TSRST) results showed that the control mix performed slightly better than the CRM, while the FRM performance was adversely affected with respect to the transition temperature midpoint and the maximum tensile stress temperature. Both of the RAP incorporated mixes exhibited better rutting resistance than the control mix. With regard to fatigue cracking, the CRM performed better than the FRM. It can be concluded that the RAP particle size has a considerable effect on its contribution to the total binder content, the aggregate skeleton of the mix, and ultimately the performance of the mix. In spite of the higher RAP content in the CRM versus FRM, the satisfactory performance observed for the CRM mix indicates a great potential in producing high RAP content mixes through optimizing the RAP particle size and content. The results also suggest that the black curve gradation assumption is not representative of the actual RAP particles contribution in a high RAP mix.

Laboratory designed hot mix asphalt mixtures with post-consumer Recycled Asphalt Shingles (RAS) utilizing AASHTO PP78

Historically, many state Departments of Transportation (DOTs) do not allow the use of post-consumer Recycled Asphalt Shingles (RAS) due to the high probability that they would be contaminated with asbestos. This study evaluates the performance of hot mix asphalt designed with post-consumer waste RAS provided by local supplier in Bethlehem, PA. Many construction debris recycling plants have a method to ensure their processed post-consumer shingles do not contain asbestos, making it a viable material for inclusion into asphalt pavements. AASHTO PP78, Standard Practice for Design Considerations When Using Reclaimed Asphalt Shingles (RAS) in Asphalt Mixtures, was used in the study in order to design the asphalt mixtures containing the RAS addition. This design method was developed to take into consideration the stiffness of the RAS asphalt binder to help reduce the potential for fatigue cracking. The results of the testing regiment provide guidance to local, state, and federal agencies as to the impacts of including RAS into asphalt pavements and whether to allow post-consumer waste RAS in HMA.However, the issue with utilizing this type of “substitution” specification is that it does not take into the account the quality of the asphalt binder of the RAS. AASHTO PP 78 evaluates the quality of the RAS binder, blended with the virgin asphalt binder, by recommending the solvent recovery of the RAS asphalt binder, blending it with the virgin asphalt binder at varying percentages, and then determining the asphalt binder properties – in particular the influence on the PG grade and the difference in the low temperature critical cracking temperatures (ΔTC).

Performance evaluation of the use of tire-derived fuel fly ash as mineral filler in hot mix asphalt concrete

Abstract According to deplete natural resources and need to protect the environment, the demand of a usage of waste material has significantly increased. Many studies are currently being carried out on the development of innovative and environmentally friendly materials for securing the safety of road users and improving the performance and durability of roads. For example, studies are currently being conducted on the use of waste tires as a substitute for currently used fuels. Since the development of the automobile industry, the amount of waste tire has continuously increased in accordance with the increased vehicle numbers. Tire-derived fuel (TDF) has been used as a fuel source with generated TDF fly ash. Mineral filler, made of fine mineral particles of a physical size passing the number 200 standard mesh sieve (75 micron), plays an important role in asphalt mixtures properties. This paper presents an application of TDF fly ash as filler in hot mix asphalt (HMA). In this study, the performance of TDF fly ash was confirmed through a comparison with three other mineral fillers: stone dust, cement, and hydrated lime. Various tests including Marshall stability test, moisture sensitivity test, dynamic immersion test, and a wheel tracking test were performed to investigate the difference in the behaviors of the samples with different parameters considered in this study. The results show that the mechanical performance of hot mix asphalt using TDF fly ash satisfied the quality standard specification of the Ministry of Land, Infrastructure and Transport (MOLIT), Korea. It can be concluded that the use of TDF fly ash as a mineral filler in HMA not only satisfied the mechanical properties, but also reduced the volume of the pollutants waste in the environment.